Contribution from Keith Campbell to add better support for

Drag & drop.

core/org.eclipse.cdt.ui/ChangeLog

@@ -1,3 +1,25 @@
+2003-09-21 Alain Magloire
+
+	Patch contributed by Keith Campbell.
+
+	Patch to enable dragging non-resource selections from 
+	the C/C++ Projects view.
+
+	The code has been reorganized to use the delegation pattern found in the 
+	JDT and a new LocalSelectionTransfer specific to the CDT has been 
+	introduced to avoid potential incompatibilities of using 
+	org.eclipse.ui.views.navigator.LocalSelectionTransfer.
+
+	* src/org/eclipse/cdt/internal/ui/drag/DelegatingDraAdapter.java
+	* src/org/eclipse/cdt/internal/ui/drag/FileTransferDragAdapter.java
+	* src/org/eclipse/cdt/internal/ui/drag/LocalSelectionTransferDragAdapter.java
+	* src/org/eclipse/cdt/internal/ui/drag/ResourceTransferDragAdapter.java
+	* src/org/eclipse/cdt/internal/ui/drag/TransferDragSourceListener.java
+
+	* src/org/eclipse/cdt/internal/ui/cview/CView.java
+
+	* src/org/eclipse/cdt/ui/LocalSelectionTransfer.java
+
 2003-09-21 Alain Magloire
 
 	Bug #41960, The asm editor did not know about '#' comment style

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/CUIMessages.properties

@@ -9,4 +9,6 @@
 # Rational Software - Initial API and implementation
 ###############################################################################
 
-ExceptionDialog.seeErrorLogMessage= See error log for more details.
+Drag.move.problem.title=Drag and Drop Problem
+Drag.move.problem.message={0} is read only. Do you still wish to delete it?
+ExceptionDialog.seeErrorLogMessage=See error log for more details.

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/cview/CView.java

@@ -24,6 +24,10 @@ import org.eclipse.cdt.internal.core.model.CProject;
 import org.eclipse.cdt.internal.core.model.TranslationUnit;
 import org.eclipse.cdt.internal.ui.IContextMenuConstants;
 import org.eclipse.cdt.internal.ui.StandardCElementLabelProvider;
+import org.eclipse.cdt.internal.ui.drag.DelegatingDragAdapter;
+import org.eclipse.cdt.internal.ui.drag.FileTransferDragAdapter;
+import org.eclipse.cdt.internal.ui.drag.ResourceTransferDragAdapter;
+import org.eclipse.cdt.internal.ui.drag.TransferDragSourceListener;
 import org.eclipse.cdt.internal.ui.editor.FileSearchAction;
 import org.eclipse.cdt.internal.ui.editor.FileSearchActionInWorkingSet;
 import org.eclipse.cdt.internal.ui.editor.OpenIncludeAction;
@@ -33,6 +37,7 @@ import org.eclipse.cdt.internal.ui.util.EditorUtility;
 import org.eclipse.cdt.internal.ui.util.ProblemTreeViewer;
 import org.eclipse.cdt.ui.CElementContentProvider;
 import org.eclipse.cdt.ui.CUIPlugin;
+import org.eclipse.cdt.ui.LocalSelectionTransfer;
 import org.eclipse.cdt.ui.PreferenceConstants;
 import org.eclipse.core.resources.ICommand;
 import org.eclipse.core.resources.IContainer;
@@ -123,7 +128,6 @@ import org.eclipse.ui.views.framelist.ForwardAction;
 import org.eclipse.ui.views.framelist.FrameList;
 import org.eclipse.ui.views.framelist.GoIntoAction;
 import org.eclipse.ui.views.framelist.UpAction;
-import org.eclipse.ui.views.navigator.LocalSelectionTransfer;
 
 
 
@@ -365,14 +369,31 @@ public class CView extends ViewPart implements IMenuListener, ISetSelectionTarge
 	 */
 	void initDragAndDrop() {
 		int ops = DND.DROP_COPY | DND.DROP_MOVE;
-		Transfer[] transfers = new Transfer[] {
-			ResourceTransfer.getInstance(),
-			FileTransfer.getInstance(),
-			LocalSelectionTransfer.getInstance(),
-			PluginTransfer.getInstance() };
 
-		viewer.addDragSupport(ops, transfers, new CViewDragAdapter((ISelectionProvider)viewer));
+		Transfer[] dragTransfers =
-		viewer.addDropSupport(ops, transfers, new CViewDropAdapter(viewer));
+			new Transfer[] {
+				ResourceTransfer.getInstance(),
+				FileTransfer.getInstance(),
+				LocalSelectionTransfer.getInstance(),
+				PluginTransfer.getInstance()};
+
+		TransferDragSourceListener[] dragListeners =
+			new TransferDragSourceListener[] {
+				new ResourceTransferDragAdapter(viewer),
+				new org.eclipse.cdt.internal.ui.drag.LocalSelectionTransferDragAdapter(viewer),
+				new FileTransferDragAdapter(viewer)};
+
+		viewer.addDragSupport(ops, dragTransfers, new DelegatingDragAdapter(viewer, dragListeners));
+
+		Transfer[] dropTransfers =
+			new Transfer[] {
+				ResourceTransfer.getInstance(),
+				FileTransfer.getInstance(),
+				LocalSelectionTransfer.getInstance(),
+				PluginTransfer.getInstance()};
+
+		viewer.addDropSupport(ops, dropTransfers, new CViewDropAdapter(viewer));
+
 	}
 
 	/** 

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/cview/CViewDragAdapter.java

@@ -1,219 +0,0 @@
-package org.eclipse.cdt.internal.ui.cview;
-
-/*
- * (c) Copyright IBM Corp. 2000, 2001.
- * All Rights Reserved.
- */
-
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
-
-import org.eclipse.core.resources.IFile;
-import org.eclipse.core.resources.IFolder;
-import org.eclipse.core.resources.IResource;
-import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.IAdaptable;
-import org.eclipse.core.runtime.IPath;
-import org.eclipse.jface.viewers.ISelection;
-import org.eclipse.jface.viewers.ISelectionProvider;
-import org.eclipse.jface.viewers.IStructuredSelection;
-import org.eclipse.swt.dnd.DND;
-import org.eclipse.swt.dnd.DragSource;
-import org.eclipse.swt.dnd.DragSourceAdapter;
-import org.eclipse.swt.dnd.DragSourceEvent;
-import org.eclipse.swt.dnd.FileTransfer;
-import org.eclipse.swt.dnd.TransferData;
-import org.eclipse.swt.widgets.Control;
-import org.eclipse.swt.widgets.Shell;
-import org.eclipse.ui.actions.ReadOnlyStateChecker;
-import org.eclipse.ui.part.ResourceTransfer;
-import org.eclipse.ui.views.navigator.LocalSelectionTransfer;
-
-/**
- * Implements drag behaviour when items are dragged out of the
- * resource navigator.
- */
-class CViewDragAdapter extends DragSourceAdapter {
-	private final ISelectionProvider selectionProvider;
-	private static final int typeMask = IResource.FOLDER | IResource.FILE;
-	private TransferData lastDataType; 	
-	private static final String CHECK_MOVE_TITLE = "Drag and Drop Problem"; //$NON-NLS-1$
-	private static final String CHECK_DELETE_MESSAGE = "{0} is read only. Do you still wish to delete it?"; //$NON-NLS-1$
-
-
-	/**
-	 * Invoked when an action occurs. 
-	 * Argument context is the Window which contains the UI from which this action was fired.
-	 * This default implementation prints the name of this class and its label.
-	 * @see DragSourceListener#dragFinished(org.eclipse.swt.dnd.DragSourceEvent)
-	 */
-	public void dragFinished(DragSourceEvent event) {
-		LocalSelectionTransfer.getInstance().setSelection(null);
-
-		if (event.doit == false)
-			return;
-
-		if (event.detail == DND.DROP_MOVE) {
-			//never delete resources when dragging outside Eclipse. 
-			//workaround for bug 30543.
-			if (lastDataType != null && FileTransfer.getInstance().isSupportedType(lastDataType))
-				return;
-			
-			IResource[] resources = getSelectedResources();	
-			DragSource dragSource = (DragSource) event.widget;
-			Control control = dragSource.getControl();
-			Shell shell = control.getShell();
-			ReadOnlyStateChecker checker;
-			
-			if (resources == null || resources.length == 0)
-				return;
-			
-			checker = new ReadOnlyStateChecker(shell, CHECK_MOVE_TITLE, CHECK_DELETE_MESSAGE);
-			resources = checker.checkReadOnlyResources(resources);		
-			//delete the old elements
-			for (int i = 0; i < resources.length; i++) {
-				try {
-					resources[i].delete(IResource.KEEP_HISTORY | IResource.FORCE, null);
-				} catch (CoreException e) {
-					e.printStackTrace();
-				}
-			}
-		} else if (event.detail == DND.DROP_TARGET_MOVE) {
-			IResource[] resources = getSelectedResources();
-
-			// file moved for us by OS, no need to delete the resources, just
-			// update the view
-			if (resources == null)
-				return;
-			for (int i = 0; i < resources.length; i++) {
-				try {
-					resources[i].refreshLocal(IResource.DEPTH_INFINITE, null);
-				} catch (CoreException e) {
-					e.printStackTrace();
-				}
-			}
-		}
-	}
-
-	/*
-	 * @see DragSourceListener#dragSetData(org.eclipse.swt.dnd.DragSourceEvent)
-	 */
-	public void dragSetData(DragSourceEvent event) {
-		IResource[] resources = getSelectedResources();
-		
-		if (resources == null || resources.length == 0)
-			return;
-
-		lastDataType = event.dataType;
-		//use local selection transfer if possible
-		if (LocalSelectionTransfer.getInstance().isSupportedType(event.dataType)) {
-			event.data = LocalSelectionTransfer.getInstance().getSelection();
-			return;
-		}
-		//use resource transfer if possible
-		if (ResourceTransfer.getInstance().isSupportedType(event.dataType)) {
-			event.data = resources;
-			return;
-		}
-		//resort to a file transfer
-		if (!FileTransfer.getInstance().isSupportedType(event.dataType))
-			return;
-
-		// Get the path of each file and set as the drag data
-		final int length = resources.length;
-		int actualLength = 0; 
-		String[] fileNames = new String[length];
-		for (int i = 0; i < length; i++) {
-			IPath location = resources[i].getLocation();
-			// location may be null. See bug 29491.
-			if (location != null) 
-				fileNames[actualLength++] = location.toOSString();
-		}
-		if (actualLength == 0)
-			return;
-		// was one or more of the locations null?
-		if (actualLength < length) {
-			String[] tempFileNames = fileNames;
-			fileNames = new String[actualLength];
-			for (int i = 0; i < actualLength; i++)
-				fileNames[i] = tempFileNames[i];
-		}
-		event.data = fileNames;
-	}
-
-	/*
-	 * @see DragSourceListener#dragStart(org.eclipse.swt.dnd.DragSourceEvent)
-	 */
-	public void dragStart(DragSourceEvent event) {
-		lastDataType = null;
-		// Workaround for 1GEUS9V
-		DragSource dragSource = (DragSource) event.widget;
-		Control control = dragSource.getControl();
-		if (control != control.getDisplay().getFocusControl()) {
-			event.doit = false;
-			return;
-		}
-
-		IStructuredSelection selection =
-			(IStructuredSelection) selectionProvider.getSelection();
-		for (Iterator i = selection.iterator(); i.hasNext();) {
-			Object next = i.next();
-			if (next instanceof IAdaptable) {
-				next = ((IAdaptable) next).getAdapter(IResource.class);
-			}
-			if (!(next instanceof IFile || next instanceof IFolder)) {
-				event.doit = false;
-				return;
-			}
-		}
-		if (selection.isEmpty()) {
-			event.doit = false;
-			return;
-		}
-		LocalSelectionTransfer.getInstance().setSelection(selection);
-		event.doit = true;
-	}
-	
-
-
-	private IResource[] getSelectedResources() {
-		ISelection selection = selectionProvider.getSelection();
-		List resources = new ArrayList();
-
-		// Sanity checks
-		if (selection == null || !(selection instanceof IStructuredSelection) || selection.isEmpty()) {
-			return null;
-		}
-
-		IStructuredSelection structuredSelection = (IStructuredSelection) selection;
-
-		// loop through list and look for matching items
-		for (Iterator enum = structuredSelection.iterator(); enum.hasNext();) {
-			Object object = enum.next();
-			IResource resource = null;
-
-			if (object instanceof IResource) {
-				resource = (IResource) object;
-			} else if (object instanceof IAdaptable) {
-				resource = (IResource) ((IAdaptable) object).getAdapter(IResource.class);
-			}
-			if (resource != null && (resource.getType() & typeMask) != 0) {
-				resources.add(resource);
-			}
-		}
-
-		IResource[] result = new IResource[resources.size()];
-		resources.toArray(result);
-
-		return result;
-	}
-
-	/**
-	 * CViewDragAction constructor.
-	 */
-	public CViewDragAdapter(ISelectionProvider provider) {
-		super();
-		selectionProvider = provider;
-	}
-}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/drag/DelegatingDragAdapter.java

@@ -0,0 +1,140 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.ui.drag;
+
+import java.util.Arrays;
+
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.swt.dnd.DragSource;
+import org.eclipse.swt.dnd.DragSourceEvent;
+import org.eclipse.swt.dnd.DragSourceListener;
+import org.eclipse.swt.dnd.Transfer;
+import org.eclipse.swt.dnd.TransferData;
+import org.eclipse.swt.widgets.Control;
+
+/**
+ * A delegating drag adapter negotiates between a set of <code>TransferDragSourceListener</code>s
+ * On <code>dragStart</code> the adapter determines the listener to be used for any further
+ * <code>drag*</code> callbacks.
+ */
+public class DelegatingDragAdapter implements DragSourceListener {
+	private final ISelectionProvider provider;
+	private final TransferDragSourceListener[] listeners;
+	private final boolean[] actives;
+	private TransferDragSourceListener selected;
+
+	public DelegatingDragAdapter(
+		ISelectionProvider provider,
+		TransferDragSourceListener[] listeners) {
+		super();
+		Assert.isNotNull(provider);
+		Assert.isNotNull(listeners);
+		this.provider = provider;
+		this.listeners = listeners;
+		this.actives = new boolean[listeners.length];
+		this.selected = null;
+	}
+
+	/* non Java-doc
+	 * @see DragSourceListener
+	 */
+	public void dragStart(DragSourceEvent event) {
+		selected = null;
+
+		if (provider.getSelection().isEmpty()) {
+			event.doit = false;
+			return;
+		}
+
+		// Workaround for 1GEUS9V
+		final DragSource dragSource = (DragSource) event.widget;
+		final Control control = dragSource.getControl();
+
+		if (control != control.getDisplay().getFocusControl()) {
+			event.doit = false;
+			return;
+		}
+
+		final Object saveData = event.data;
+		final boolean saveDoit = event.doit;
+		final int listenerCount = listeners.length;
+
+		int transferCount = 0;
+
+		for (int i = 0; i < listenerCount; ++i) {
+			TransferDragSourceListener listener = listeners[i];
+
+			event.data = saveData;
+			event.doit = saveDoit;
+
+			listener.dragStart(event);
+
+			if (actives[i] = event.doit)
+				++transferCount;
+		}
+
+		event.data = saveData;
+
+		if (event.doit = (transferCount != 0)) {
+			Transfer[] transferArray = new Transfer[transferCount];
+
+			for (int i = listenerCount; --i >= 0;)
+				if (actives[i])
+					transferArray[--transferCount] = listeners[i].getTransfer();
+
+			dragSource.setTransfer(transferArray);
+		}
+	}
+
+	/* non Java-doc
+	 * @see DragSourceListener
+	 */
+	public void dragSetData(DragSourceEvent event) {
+		selected = getListener(event.dataType);
+
+		if (selected != null)
+			selected.dragSetData(event);
+	}
+
+	/* non Java-doc
+	 * @see DragSourceListener
+	 */
+	public void dragFinished(DragSourceEvent event) {
+		try {
+			// If the user presses Escape then we get a dragFinished
+			// without getting a dragSetData before.
+			if (selected == null)
+				selected = getListener(event.dataType);
+
+			if (selected != null)
+				selected.dragFinished(event);
+		} finally {
+			Arrays.fill(actives, false);
+			selected = null;
+		}
+	}
+
+	private TransferDragSourceListener getListener(TransferData type) {
+		if (type != null) {
+			for (int i = 0; i < actives.length; ++i) {
+				if (actives[i]) {
+					TransferDragSourceListener listener = listeners[i];
+
+					if (listener.getTransfer().isSupportedType(type))
+						return listener;
+				}
+			}
+		}
+
+		return null;
+	}
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/drag/FileTransferDragAdapter.java

@@ -0,0 +1,186 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.ui.drag;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import org.eclipse.cdt.internal.ui.CUIMessages;
+import org.eclipse.cdt.internal.ui.util.ExceptionHandler;
+import org.eclipse.cdt.ui.CUIPlugin;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IAdaptable;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.MultiStatus;
+import org.eclipse.core.runtime.SubProgressMonitor;
+import org.eclipse.jface.dialogs.ProgressMonitorDialog;
+import org.eclipse.jface.operation.IRunnableWithProgress;
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.swt.dnd.DND;
+import org.eclipse.swt.dnd.DragSourceEvent;
+import org.eclipse.swt.dnd.FileTransfer;
+import org.eclipse.swt.dnd.Transfer;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.IWorkbench;
+import org.eclipse.ui.IWorkbenchWindow;
+import org.eclipse.ui.actions.WorkspaceModifyOperation;
+
+public class FileTransferDragAdapter implements TransferDragSourceListener {
+	private final ISelectionProvider provider;
+
+	public FileTransferDragAdapter(ISelectionProvider provider) {
+		super();
+		this.provider = provider;
+		Assert.isNotNull(provider);
+	}
+
+	public Transfer getTransfer() {
+		return FileTransfer.getInstance();
+	}
+
+	public void dragStart(DragSourceEvent event) {
+		event.doit = !getResources().isEmpty();
+	}
+
+	public void dragSetData(DragSourceEvent event) {
+		String[] locations = getResourceLocations(getResources());
+
+		event.data = locations.length != 0 ? locations : null;
+	}
+
+	public void dragFinished(DragSourceEvent event) {
+		if (event.doit) {
+			if (event.detail == DND.DROP_MOVE) {
+				// Never delete resources when dragging outside Eclipse.				
+				// See: http://bugs.eclipse.org/bugs/show_bug.cgi?id=30543
+			} else if (event.detail == DND.DROP_NONE || event.detail == DND.DROP_TARGET_MOVE) {
+				runOperation(new RefreshOperation(getResources()), true, false);
+			}
+		}
+	}
+
+	private static class RefreshOperation extends WorkspaceModifyOperation {
+		private final Set roots;
+
+		public RefreshOperation(List resources) {
+			super();
+
+			roots = new HashSet(resources.size());
+
+			for (Iterator iterator = resources.iterator(); iterator.hasNext();) {
+				IResource resource = (IResource) iterator.next();
+				IResource parent = resource.getParent();
+
+				roots.add(parent != null ? parent : resource);
+			}
+		}
+
+		public void execute(IProgressMonitor monitor) throws CoreException {
+			try {
+				monitor.beginTask(CUIMessages.getString("DragAdapter.refreshing"), roots.size()); //$NON-NLS-1$
+				MultiStatus status = new MultiStatus(CUIPlugin.getPluginId(), IStatus.OK, CUIMessages.getString("DragAdapter.problem"), null); //$NON-NLS-1$
+
+				for (Iterator iterator = roots.iterator(); iterator.hasNext();) {
+					IResource resource = (IResource) iterator.next();
+
+					try {
+						resource.refreshLocal(
+							IResource.DEPTH_ONE,
+							new SubProgressMonitor(monitor, 1));
+					} catch (CoreException e) {
+						status.add(e.getStatus());
+					}
+				}
+
+				if (!status.isOK())
+					throw new CoreException(status);
+			} finally {
+				monitor.done();
+			}
+		}
+	}
+
+	private List getResources() {
+		List result = Collections.EMPTY_LIST;
+		ISelection selection = provider.getSelection();
+
+		if (selection instanceof IStructuredSelection) {
+			IStructuredSelection structured = (IStructuredSelection) selection;
+
+			result = new ArrayList(structured.size());
+
+			for (Iterator iterator = structured.iterator(); iterator.hasNext();) {
+				Object object = iterator.next();
+				IResource resource = null;
+
+				if (object instanceof IResource)
+					resource = (IResource) object;
+				else if (object instanceof IAdaptable)
+					resource = (IResource) ((IAdaptable) object).getAdapter(IResource.class);
+
+				if (resource != null)
+					result.add(resource);
+			}
+		}
+
+		return result;
+	}
+
+	private static String[] getResourceLocations(List resources) {
+		final int count = resources.size();
+		final List locations = new ArrayList(count);
+
+		for (Iterator iterator = resources.iterator(); iterator.hasNext();) {
+			IResource resource = (IResource) iterator.next();
+			IPath location = resource.getLocation();
+
+			if (location != null)
+				locations.add(location.toOSString());
+		}
+
+		String[] result = new String[locations.size()];
+
+		locations.toArray(result);
+
+		return result;
+	}
+
+	private static void runOperation(
+		IRunnableWithProgress operation,
+		boolean fork,
+		boolean cancelable) {
+		try {
+			IWorkbench workbench = CUIPlugin.getDefault().getWorkbench();
+			IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();
+			Shell parent = window.getShell();
+
+			new ProgressMonitorDialog(parent).run(fork, cancelable, operation);
+		} catch (InterruptedException e) {
+			// Do nothing. Operation has been canceled by user.
+		} catch (InvocationTargetException e) {
+			String message = CUIMessages.getString("Problem while moving or copying files."); //$NON-NLS-1$
+			String title = CUIMessages.getString("Drag & Drop"); //$NON-NLS-1$
+
+			ExceptionHandler.handle(e, title, message);
+		}
+	}
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/drag/LocalSelectionTransferDragAdapter.java

@@ -0,0 +1,60 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.ui.drag;
+
+import org.eclipse.cdt.ui.LocalSelectionTransfer;
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.swt.dnd.DragSourceEvent;
+import org.eclipse.swt.dnd.Transfer;
+
+public class LocalSelectionTransferDragAdapter implements TransferDragSourceListener {
+	private final ISelectionProvider provider;
+	private final LocalSelectionTransfer transfer;
+
+	public LocalSelectionTransferDragAdapter(ISelectionProvider provider) {
+		super();
+		this.provider = provider;
+		this.transfer = LocalSelectionTransfer.getInstance();
+		Assert.isNotNull(provider);
+		Assert.isNotNull(transfer);
+	}
+
+	/* (non-Javadoc)
+	 * @see DragSourceListener#dragStart
+	 */
+	public void dragStart(DragSourceEvent event) {
+		transfer.setSelection(provider.getSelection());
+
+		event.doit = true;
+	}
+
+	/* (non-Javadoc)
+	 * @see DragSourceListener#dragSetData
+	 */
+	public void dragSetData(DragSourceEvent event) {
+		event.data = transfer.isSupportedType(event.dataType) ? transfer.getSelection() : null;
+	}
+
+	/* (non-Javadoc)
+	 * @see DragSourceListener#dragFinished
+	 */
+	public void dragFinished(DragSourceEvent event) {
+		transfer.setSelection(null);
+	}
+
+	/* (non-Javadoc)
+	 * @see TransferDragSourceListener#getTransfer
+	 */
+	public Transfer getTransfer() {
+		return transfer;
+	}
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/drag/ResourceTransferDragAdapter.java

@@ -0,0 +1,147 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials 
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.ui.drag;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.cdt.internal.ui.CUIMessages;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IAdaptable;
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.swt.dnd.DND;
+import org.eclipse.swt.dnd.DragSource;
+import org.eclipse.swt.dnd.DragSourceEvent;
+import org.eclipse.swt.dnd.Transfer;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.actions.ReadOnlyStateChecker;
+import org.eclipse.ui.part.ResourceTransfer;
+
+/**
+ * A drag adapter that transfers the current selection as </code>
+ * IResource</code>. Only those elements in the selection are part 
+ * of the transfer which can be converted into an <code>IResource
+ * </code>.
+ */
+public class ResourceTransferDragAdapter implements TransferDragSourceListener {
+	private final ISelectionProvider provider;
+
+	/**
+	 * Creates a new ResourceTransferDragAdapter for the given selection provider.
+	 *
+	 * @param provider the selection provider to access the viewer's selection
+	 */
+	public ResourceTransferDragAdapter(ISelectionProvider provider) {
+		super();
+		this.provider = provider;
+		Assert.isNotNull(provider);
+	}
+
+	public Transfer getTransfer() {
+		return ResourceTransfer.getInstance();
+	}
+
+	public void dragStart(DragSourceEvent event) {
+		event.doit = false;
+
+		ISelection selection = provider.getSelection();
+
+		if (selection instanceof IStructuredSelection) {
+			IStructuredSelection structured = (IStructuredSelection) selection;
+
+			for (Iterator iterator = structured.iterator(); iterator.hasNext();) {
+				Object element = iterator.next();
+
+				if (element instanceof IAdaptable) {
+					IAdaptable adaptable = (IAdaptable) element;
+					IResource resource = (IResource) adaptable.getAdapter(IResource.class);
+
+					if (resource == null) {
+						event.doit = false;
+						break;
+					}
+
+					// this will stick unless a later part of the
+					// selection isn't adaptable into a resource
+					event.doit = true;
+				}
+			}
+		}
+	}
+
+	public void dragSetData(DragSourceEvent event) {
+		event.data = getSelectedResources();
+	}
+
+	public void dragFinished(DragSourceEvent event) {
+		if (event.doit && event.detail == DND.DROP_MOVE) {
+			IResource[] resources = getSelectedResources();
+
+			if (resources.length == 0)
+				return;
+
+			DragSource dragSource = (DragSource) event.widget;
+			Control control = dragSource.getControl();
+			Shell shell = control.getShell();
+			String title = CUIMessages.getString("Drag.move.problem.title"); //$NON-NLS-1$
+			String message = CUIMessages.getString("Drag.move.problem.message"); //$NON-NLS-1$
+
+			ReadOnlyStateChecker checker = new ReadOnlyStateChecker(shell, title, message);
+
+			resources = checker.checkReadOnlyResources(resources);
+
+			// delete the old elements
+			for (int i = 0; i < resources.length; ++i) {
+				try {
+					resources[i].delete(IResource.KEEP_HISTORY | IResource.FORCE, null);
+				} catch (CoreException e) {
+					e.printStackTrace();
+				}
+			}
+		}
+	}
+
+	private IResource[] getSelectedResources() {
+		List resources = Collections.EMPTY_LIST;
+		ISelection selection = provider.getSelection();
+
+		if (selection instanceof IStructuredSelection) {
+			IStructuredSelection structured = (IStructuredSelection) selection;
+
+			resources = new ArrayList(structured.size());
+
+			for (Iterator iterator = structured.iterator(); iterator.hasNext();) {
+				Object element = iterator.next();
+
+				if (element instanceof IAdaptable) {
+					IAdaptable adaptable = (IAdaptable) element;
+					IResource resource = (IResource) adaptable.getAdapter(IResource.class);
+
+					if (resource != null)
+						resources.add(resource);
+				}
+			}
+		}
+
+		IResource[] result = new IResource[resources.size()];
+		resources.toArray(result);
+
+		return result;
+	}
+
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/drag/TransferDragSourceListener.java

@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.ui.drag;
+
+import org.eclipse.swt.dnd.DragSourceListener;
+import org.eclipse.swt.dnd.Transfer;
+
+/**
+ * A special drag source listener which is typed with a <code>TransferData</code>.
+ */
+public interface TransferDragSourceListener extends DragSourceListener {
+	/**
+	 * Returns the transfer used by this drag source.
+	 */
+	public Transfer getTransfer();
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/LocalSelectionTransfer.java

@@ -0,0 +1,74 @@
+package org.eclipse.cdt.ui;
+
+import java.util.Arrays;
+
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.swt.dnd.ByteArrayTransfer;
+import org.eclipse.swt.dnd.TransferData;
+
+/**
+ * @author kcampbell
+ */
+public class LocalSelectionTransfer extends ByteArrayTransfer {
+	private static final LocalSelectionTransfer INSTANCE = new LocalSelectionTransfer();
+
+	private final String typeName;
+	private final int typeId;
+	private ISelection selection;
+
+	private LocalSelectionTransfer() {
+		super();
+		// Try to ensure that different Eclipse applications use different "types" of <code>LocalSelectionTransfer</code>
+		typeName = "cdt-local-selection-transfer-format" + System.currentTimeMillis(); //$NON-NLS-1$;
+		typeId = registerType(typeName);
+		selection = null;
+	}
+
+	/**
+	 * Returns the singleton.
+	 */
+	public static LocalSelectionTransfer getInstance() {
+		return INSTANCE;
+	}
+
+	/**
+	 * Sets the transfer data for local use.
+	 */
+	public void setSelection(ISelection selection) {
+		this.selection = selection;
+	}
+
+	/**
+	 * Returns the local transfer data.
+	 */
+	public ISelection getSelection() {
+		return selection;
+	}
+
+	public void javaToNative(Object object, TransferData transferData) {
+		// No encoding needed since this is a hardcoded string read and written in the same process.
+		// See nativeToJava below
+		super.javaToNative(typeName.getBytes(), transferData);
+	}
+
+	public Object nativeToJava(TransferData transferData) {
+		Object result = super.nativeToJava(transferData);
+
+		// No decoding needed: see javaToNative above.
+		Assert.isTrue(result instanceof byte[] && Arrays.equals(typeName.getBytes(), (byte[]) result));
+
+		return selection;
+	}
+
+	/**
+	 * The type id used to identify this transfer.
+	 */
+	protected int[] getTypeIds() {
+		return new int[] { typeId };
+	}
+
+	protected String[] getTypeNames() {
+		return new String[] { typeName };
+	}
+}